JCLOUDS-410. Correctly override getInput

Payload.getInput must always call openStream to handle overridden
methods correctly.  Previously this caused errors in jclouds-chef in
BaseCipherPayload.

core/src/main/java/org/jclouds/io/payloads/BaseCipherPayload.java

@@ -44,8 +44,8 @@ public abstract class BaseCipherPayload extends DelegatingPayload {
    public abstract Cipher initializeCipher(Key key);
 
    @Override
-   public CipherInputStream openStream() {
-      return new CipherInputStream(super.getInput(), initializeCipher(key));
+   public CipherInputStream openStream() throws IOException {
+      return new CipherInputStream(super.openStream(), initializeCipher(key));
    }
 
    @Override

core/src/main/java/org/jclouds/io/payloads/DelegatingPayload.java

@@ -22,6 +22,8 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
+import com.google.common.base.Throwables;
+
 import org.jclouds.io.MutableContentMetadata;
 import org.jclouds.io.Payload;
 
@@ -50,7 +52,11 @@ public class DelegatingPayload implements Payload {
     */
    @Override
    public InputStream getInput() {
-      return delegate.getInput();
+      try {
+         return openStream();
+      } catch (IOException ioe) {
+         throw Throwables.propagate(ioe);
+      }
    }
 
    /**

core/src/test/java/org/jclouds/io/payloads/MultipartFormTest.java

@@ -74,8 +74,8 @@ public class MultipartFormTest {
       }
 
       @Override
-      public InputStream getInput() {
-         return realPayload.getInput();
+      public InputStream openStream() throws IOException {
+         return realPayload.openStream();
       }
 
       @Override